commit 4c8ab8b4415d129d0283d7d0d9a5789163ec8d5e
Author: Rémi Verschelde <rverschelde@gmail.com>
Date:   Sat May 27 16:38:46 2017 +0200

    openssl: Define WIN32_LEAN_AND_MEAN on Windows
    
    This avoids namespace collisions with things such as X509_NAME.
    Also force include of necessary definitions in `crypto/o_str.c`
    which seem missing on MSVC (but work on MinGW).

diff --git a/thirdparty/openssl/crypto/o_str.c b/thirdparty/openssl/crypto/o_str.c
index 7e61cde85..1854798e2 100644
--- a/thirdparty/openssl/crypto/o_str.c
+++ b/thirdparty/openssl/crypto/o_str.c
@@ -59,6 +59,9 @@
 
 #include <ctype.h>
 #include <e_os.h>
+// -- GODOT start --
+#include <openssl/opensslconf.h>
+// -- GODOT end --
 #include "o_str.h"
 
 #if !defined(OPENSSL_IMPLEMENTS_strncasecmp) && \
diff --git a/thirdparty/openssl/openssl/opensslconf.h b/thirdparty/openssl/openssl/opensslconf.h
index f533508b1..19fad2342 100644
--- a/thirdparty/openssl/openssl/opensslconf.h
+++ b/thirdparty/openssl/openssl/opensslconf.h
@@ -7,6 +7,20 @@ extern "C" {
 /* OpenSSL was configured with the following options: */
 #ifndef OPENSSL_DOING_MAKEDEPEND
 
+// -- GODOT start --
+#if defined(OPENSSL_SYS_WINDOWS)
+# define WIN32_LEAN_AND_MEAN
+// Seems like we have troubles properly using the logic in e_os2.h
+# if defined(_WIN32)
+#  define OPENSSL_SYS_WIN32
+#  define OPENSSL_SYSNAME_WIN32
+# endif
+# if defined(_WIN64)
+#  define OPENSSL_SYS_WIN64
+#  define OPENSSL_SYSNAME_WIN64
+# endif
+#endif
+// -- GODOT end --
 
 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
 # define OPENSSL_NO_EC_NISTP_64_GCC_128
